Kainji Dam: A Masterpiece, that took 20,000 men from nine different nationalities to construct.

Dam being a structure across a stream, river, or estuary is built to retain water. Dams are being built to meet demands for water for human consumption, irrigation, or industry; to actually reduce the peak discharge of flood water; to increase the depth of water in a river so as to improve navigation; to increase available water storage for generating hydroelectric power. Incidentally, it can be provided for recreation. A dam is also described as the central structure in a multipurpose scheme aiming at the conservation of water resources. The earliest recorded dam in history is believed to have been on the Nile River at Kosheish, where a 49-foot (15metre) high masonry structure was built about 2900 BC to supply water to King Menes' capital at Memphis. The oldest dam in use is a rock-fill structure about 20 feet high on the Orontes in Syria, built about 1300 BC. 

Dams are actually categorized into several distinct classes, by profile and by building material. Decision as to which type of dam to build depends largely on the foundation conditions in the valley and the construction materials available. Broadly, the choice of materials now lies between concrete, soils, and rock fill. Secondary works at a dam may include spillways, gates, or valves to control the discharge of surplus water downstream from the dam; an intake structure conducting water to a power station or to canals, tunnels, or pipelines for more distant use; provision for evacuating silt carried into the reservoir; and means for permitting ships or fish to pass the dam. The multipurpose dam holds special importance in less developed countries, where a small nation may reap enormous benefits in agriculture and industry from a single dam.

Kainji Dam was built in 1968, it was actually constructed across the Niger River, in Niger State, in North Central Nigeria (There are three major dams in Niger State, Nigeria. The Kainji Dam built in 1968, Jebba Dam built in 1985 and Shiroro Dam built in 1990. A fourth dam is being built at Zungeru, also in Niger State). Kainji Dam is the largest of the dams on the Niger, is 215 feet (66 m) high and 1,800 feet (550 m) across and provides electrical power, improved river navigation upstream to Yelwa in Kebbi state, water control of the Niger down to the Kaduna River confluence, and a road across the Niger. Its reservoir, Kainji Lake, supports irrigation and fishing projects in the states in which it lies. On its western shore, Lake Kainji National Park serves as a recreation centre. The Niger is also a source of hydroelectricity.

The Kainji Dam has a concrete main dam with rockfill embankments and a saddle dam. The saddle dam protects the main dam during flooding. There are four spillways with hydraulic operated gates of 15.2 x 15.2 m (50 x 50 ft), which could be opened to control flood and also to release water for use at the Jebba Dam downstream. It is 85.5 m (215 ft) in height and about 8 km (5 miles) in length. The lake is supplied with water from the upper Niger River and it flows from Futa Djarlon Island through Guinea, Mali, Sierra Leone, Senegal and Niger. The reservoir lake stretches some 136 km upstream and has a breadth of 24 km at its widest point. The maximum head elevation is 141.7 m (465 ft) and maximum tail elevation is 104m (330 ft). The lake has a total capacity of 15 billion cubic meters covering an area of 1270 square kilometres. The lake is one of the longest dams in the world.

Most of the structure is made from earth, but the centre section, housing the hydroelectric turbines, was built from concrete. A retrieved information from daily trust online states that the dam was designed to have a generating capacity of 960 Megawatts; however, only 8 of its 12 turbines have been installed, reducing the capacity to 760 Megawatts. The dam generates electricity for all the large cities in Nigeria. Some of the electricity is sold to the neighbouring country of Niger. In addition, occasional droughts have made the Niger's water flow unpredictable, diminishing the dam's electrical output. The dam has a single-lock chamber capable of lifting barges 49 metres (161 ft).

Kainji Lake measures about 135 kilometres (84 mi) long and about 30 kilometres (19 mi) at its widest point, and supports irrigation and a local fishing industry. Africasia.com also reported that in 1999, uncoordinated opening of floodgates led to local flooding of about 60 villages.

The dam which took almost five years to construct was built by Impregilo, a consortium of three Italian firms. It took 20,000 men of nine different nationalities to construct it. US$209 million was the total estimated cost, with one-quarter of this amount to resettle people displaced by the construction of the dam and its reservoir, Kainji Lake.

Human embryonic stem cells cloned

A scientist removes the nucleus from a human egg using a pipette. This is the first step to making personalized embryonic stem cells.

Another breakthrough in science, after more than a decade of false starts, National Geographic reports that, Oregon Health and Science University researchers announced they had  cloned human embryos and collected stem cells from them. They also grew the cells into specialized skin and heart cells, a first step toward using them in transplant medicine. The key to the team's success turned out to be the addition of caffeine to the cloning process. Now researchers will seek to discover whether these cells or similar "induced" stem cells, made without embryos, will have the most medical use.

Lassa fever: The Rat’s role and preventive measures against them

The word ‘Lassa’ is a name of a town in Borno State, Nigeria. The word was used because the virus was first described in the town in 1969. Lassa fever is a member of arenaviridae virus family. The virus is endemic in West African countries. It has been described has an acute viral hemorrhagic fever caused by the Lassa virus. Lassa virus is primarily hosted by Natal Multi-mammate rats (Mastomys natalensis) an animal indigenous to most of Sub-Sahara Africa. The virus is probably transmitted by contact with feces or urine of animals. With this description, the virus is termed zoonotic (transmitted from animals). As deadly as the virus is, inhalation of any tiny particle of infected material (aerosol) is significant for exposure. It is easily transmitted from human to another human through blood, urine, semen, airborne route and breast milk. Symptoms of the disease include fever, facial swelling, and muscle fatigue, as well as conjunctivitis and mucosal bleeding. The other symptoms arising from the affected organs are: Gastrointestinal tract Nausea Vomiting (bloody), Diarrhea (bloody), Stomach ache, difficulty swallowing, abnormally high heart rate, Cough Chest pain and Unilateral or bilateral hearing deficit Seizures. A keen interest is shown in rats as they are the vectors, so preventive measures against them will drastically reduce the rate at which the virus is being transferred.

It is known that rats are ubiquitous in this part of the country; even the urban cities have them in their closet. Rats being rodent, feast on anything that comes their way (they feed on grains, tubers, clothes, papers etc.) and this have actually made the transfer of the virus very easy, as this brings us closer to them. At this point, the Rat is termed the sole distributor of the virus, to back it up, research also show that the rat body is the natural reservoir of the Lassa fever virus, so I would say they are Lassa fever rats.

The measures to be put in place include;

Proper storage of grains and all other food items

All food items must be kept in a sealed and well ventilated environment. And the store where these foods are kept must be neat and tidy always, as rats find it very difficult to stay in a stuffed-free environment.

Personal hygiene

Sanitation must be carried out frequently, to avert rats at all cost. We must also make sure all cooking utensils and other household materials are always washed before being used, as the urine and feces from the rat is enough for exposure to the virus. We must also dispose all materials, especially food items we suspect to have been in contact with the rats. Unfinished foods must be kept in a save place not to allow rats get in contact with them. As the popular saying cleanliness also drives the doctor away.

Rat traps and rodents control chemicals can also be put in place to capture them, but in using chemicals to control rat, make sure adequate, measures are followed to avert accidents (read instructions carefully). Don’t forget to keep these chemicals out of reach of children.

Reference:

Wikipedia.

Insecticides are more deadly than mosquitoes when misapplied.

It is presently of no doubt that the female Anopheles mosquito is responsible for the transmission of the protozoan parasite (plasmodium spp.) which causes malaria in Humans. Malaria before the breakthrough in its prevention and cure, had records of millions of death, but thanks to the relentless efforts of scientists who discovered the preventive and curative measures. Various things that were put into place include the introduction of the antimalarial drugs which were solely to curb the protozoan parasites, while mosquito nets and insecticides were for the purpose of curbing the activities of the vector which is the female anopheles mosquito.

Unfortunately, there has been an alarming rate in the misapplication of the insecticides. We tend not to realize that these insecticides contains chemicals which when accumulated into our body system becomes a toxic dose that damage the body system and eventually leading to death.

Insecticides lead to the following, when misapplied;

Chronic poisoning: Exposure to small amounts of insecticides over a long period of time can lead to chronic poisoning. This often causes physical and neurological effects such as twitching, nervousness, slow movement and a sharp decline in good health. A bad story arises when the source of the poisoning is unknown as this will eventually make the treatment difficult. Cases of cancer aren’t exempted too.

Allergic reaction: Within a short time frame, allergic reaction might occur when a person is exposed to the insecticide (University of Missouri extension’s website), especially those that are very sensitive to chemicals. The allergic reactions usually include skin and nose irritation, watering of the eyes and difficulty breathing similar to an asthma attack. But not all persons are sensitive to chemicals.

Insecticide runoffs: This arises when the insecticides are sprayed aimlessly onto eroding soils or when heavy rain falls right after application. A person drinking from the contaminated water, experience bad effect from the chronic poisoning. Also consumption of the contaminated plants will also lead to chronic poisoning.

It is therefore advisable to use or spray insecticides when there is little chance of rain and no wind to prevent the chemicals from moving aimlessly (drifting). It is also of importance to stay away from the sprayed area for about 6 to 7 hours so as to avoid being exposed to the chemical. Lastly keep out of reach of children and don’t make insecticides body sprays!!!

References;

• The cooperative extension system: symptoms of pesticide poisoning.
• University of Missouri Extension: Pesticide poisoning symptoms and first aid

How damaging are the Air Pollutants?

Air pollution arises when particulates, chemicals or biological materials are introduced into the atmosphere tocause disease, physical unease or death to humans, crops or damage our natural environment .

The extent to which this pollutant deteriorates our health, crops and environment is alarming; we do hope we have a zero air pollutant someday. The principal agents of air pollution are explained below with health hazard they cause.

Particulate Matter

They are the total particulate matter suspended in the air, with additional subcategories of particles smaller than 10 μm in diameter and particles smaller than 2.5 μm in diameter. These particulate matters can exist in solid or liquid form, and includes smoke, dust, aerosols, metallic oxides, and pollen. They have their sources from factories, combustion, construction, agricultural activities, motor vehicles, and wood burning. Inhalation of enough particulate matter over time increases the risk of chronic respiratory disease.

Lead (Pb)

The largest source of Pb in the atmosphere has been from leaded gasoline combustion, but with the gradual elimination worldwide of lead in gasoline, air Pb levels have decreased considerably. Other airborne sources include combustion of solid waste, coal, and oils, emissions from iron and steel production and lead smelters, and tobacco smoke (source of lead in tobacco is Pb-210). Exposure to Pb can affect the blood, kidneys, and nervous, immune, cardiovascular, and reproductive systems.

Sulfur dioxide (SO2)

This compound is colourless, but has a suffocating, pungent odour. The primary source of SO2 is the combustion of sulfur-containing fuels (e.g., oil and coal). Exposure to SO2 can cause the irritation of lung tissues and can damage health and materials.

Nitrogen oxides (NO and NO2)

NO2 is a reddish-brown gas with a sharp odour. This gas is sourced primarily from the vehicle traffic, and it plays a role in the formation of tropospheric ozone. Large concentrations can reduce visibility and increase the risk of acute and chronic respiratory disease.

Carbon monoxide (CO)

Carbon monoxide is an odourless, colourless gas, formed from the incomplete combustion of fuels. Thus, the largest sources of CO today are motor vehicles, motor bikes and generators. Inhalation of CO reduces the amount of oxygen in the bloodstream (it competes with the oxygen in the blood stream), and high concentrations can lead to headaches, dizziness, unconsciousness, and death.

Ozone (O3)

Tropospheric (“low-level”) ozone is a secondary pollutant formed when sunlight causes photochemical reactions involving nitrogen oxides and volatile organic compounds. Automobiles are the largest source of volatile organic compound necessary for these reactions. Ozone concentrations tend to peak in the afternoon, and can cause eye irritation, aggravation of respiratory diseases, and damage to plants and animals.